Because of an increasing awareness that high fat dietary intake can be harmful to health, attempts have been made to produce food products that are low in fat. Most of these attempts have been less than satisfactory, especially when it comes to low fat foods that are meant to "mimic" their high fat counterparts. Such has been the case with ice cream.
A noted ice cream authority (W. S. Arbuckle, in Ice Cream, Fourth Edition, 1986, AVI Publishing Company, Westport, CT at page 39) describes ice cream as a complex oil-in-water type of emulsion in which the dispersed phase is the milk fat, and the continuous phase is aqueous serum consisting of calcium caseinate-calcium phosphate micelles, serum proteins, carbohydrates and mineral salts. Despite its complexity, when properly prepared and handled, this oil-in-water emulsion can withstand the stress of freezing without losing its characteristic smoothness, body and flavor. Unfortunately, the same has not been true for most prior art low fat frozen deserts meant to "mimic" ice cream. In these products, either because it is difficult to freeze them or to retain their composition at the freezing temperature, a low fat content has usually meant a decrease or loss of desired ice cream characteristics, namely, smoothness, body and flavor.
Of the various known low fat frozen desserts, frozen yogurt is perhaps the most successufl when it comes to mimicking the desired characteristics of ice cream. Like ice cream, frozen yogurt is smooth and has an acceptable body. If additional sugar or sweetener is added to the yogurt, most consumers also feel that frozen yogurt has an acceptable tart flavor as well.
Despite these apparent similarities and many common ingredients, ice cream and cultured frozen yogurt are really quite different products. While both ice cream and yogurt begin with a liquid milk base, unlike ice cream, yogurt is not an oil-in-water emulsion. Rather, the custard-like consistency of yogurt results from acid coagulation of milk proteins following fermentation of sugars in the milk solution by lactic acid producing bacteria. More specifically, when yogurt is made, a milk solution is incubated with special bacteria that metabolize milk sugars, leaving lactic acid as a by-product. When the level of acidity of the resulting "fermenting" milk solution reaches about 0.6 percent (in terms of the lactic acid), further growth of the bacteria is inhibited and coagulation of the solids in the milk solution occurs. Knowing that the smooth, custard-like consistency of the yogurt results from acid induced coagulation of the milk solids, and is achieved before the yogurt is "frozen", it is not surprising that even low fat and non-fat yogurt can be used to make a frozen dessert having acceptable flavor, body and texture.
Unlike a yogurt, the milk solids in the non-fat dairy compositions of the present invention are not coagulated by the action of lactic acid producing bacteria, thereby giving body and texture to a frozen dessert made therefrom. (Additional body is often given to frozen yogurts by the addition of stabilizer ingredients such as sodium alginate. The alginate reacts with calcium in the yogurt, thereby producing an insoluble gel that provides an internal "skeleton" or network to support the frozen product.) In addition, unlike traditional ice creams, the non-fat dairy compositions of the present invention are not oil-in-water emulsions. In fact, they are essentially fat free. Therefore it is surprising that these non-fat non-yogurt dairy compositions can be used to produce soft and hard frozen dairy dessert products that have flavor, body and texture comparable to high quality, fat-containing ice creams.
As stated above, the present invention comprises non-fat dairy dessert compositions that can be used to make frozen dessert products having the flavor, body, and texture of ice cream. It has also been discovered that preparation of these non-fat dairy compositions requires a change in standard processing procedures in that a portion of the milk sugar in the milk solids is "caramelized" before the mix is used to make frozen dairy desserts.
The idea of caramelizing sugar is not new, nor is the idea of partially caramelizing milk sugars to make an improved yogurt. For example, to minimize the amount of sweetener that must be added to a yogurt to offset the natural tartness of the "lactic acid", U.S. Pat. No. 4,258,064 (issued Mar. 24, 1981 to T. S. Michener) teaches partial caramelization of the milk sugars prior to incubation of the dairy base mix with yogurt producing bacteria. Because the caramelized milk sugars are not fermented by the lactic acid producing bacteria, the resulting yogurt has a greater natural sweetness than conventional yogurts have.
While the idea of caramelizing milk sugars is not new, the idea that caramelized milk sugars and milk solids can be used to make non-fat, non-yogurt frozen dairy desserts is new. In addition, due to the lack of fat and therefore the inherent inability of a fat free base mix to form an oil-in-water "ice cream" type emulsion, it is surprising that the non-fat "caramelized" dairy compositions of the present invention can be used to make frozen dairy desserts that have body, texture and favor that is comparable to a good quality ice cream.